Smaller, Independently owned farms significantly increase biodiversity in crops because smaller, independently owned farms (among other things) tend to
1) seed their old crops/strains because it's free seed;
2) not share/split seed with their neighbors because they're competition and because they have their own free seed; and
3) encourage small-level cross-breeding and evolution of strains because of 1) and 2) - regular old natural genetic modification happens this way, with cross pollination, especially with wind pollinated crops like wheat (in fact, Monsanto has sued farmers for failing to license the product when neighboring farms have cross pollinated farms and led to the genetic modifications from Monsanto products for free)
Biodiversity is important in crops. Smaller farms help that. Ergo, I'd like us to help make smaller farms viable again.